Covering material



May 14, 1940. I Q E RAHR 2,200,341

COVERING MATERIAL Filed Jan. 8, 1938 4 Sheets-Sheet l OOOOOOO INVENTOR @i 6fm-57E@ EPA/qe.

BY /f 4 ATTORN EY May 14, 1940. c. E. RAHR COVERING MATERIAL Filed Jan. 8, 1938 4 Sheets-Sheet 2 INVENTOR CHESTER E @Af/R. BYeglldz A44/'f ATTORNEY May 14. 1940. c. E. RAHR 2,200,341

COVERING MATERIAL Filed Jan. 8, 1938 4 SheAets-Sheet ,3

ATTORNEY 'covERING MATERIAL Filed Jan. s, 19:58 4 sneets-sneet 4 /42 @M 5 @mm2 f @um ATTORNEY Patented May 14, 1940 UNITED STATES COVERING MATERIAL Chester E. Rahr, New York, N. Y., assignor to Certain-'feed Products Corporation, New York, N. Y., a corporation of Maryland Application January 8, 1938, Serial No. 184,018

13 Claims.

This invention relates to covering materials, especially to coverings to be exposed to the weather, such as roofing and shingles. The inventionparticularly relates to roofing materials utilizing a sheet of fibrous material as a base.

Many attempts, heretofore, have been made to produce covering materials, and particularly roof coverings with a substantial thickness. Such .materials have utilized a base sheet saturated with a waterproof or water-resistant saturant,

such as asphalt, usually carrying upon the face surface of the sheet a coating of such a protective or water resisting material. To simulate thick shingles of wood or ceramic tiles and to secure a texture in the roof which is not obtainable with the ordinary sheet roofing elements such materials have been made in various forms as shingles and shingle strips. Such endeavors have been directed, in part, to the incorporation in the asphalt coating upon the face of the satgranular or powdered form, some having an inherently light weight. Such covering materials and covering elements have been made with a 5r substantial thickness by processes which are similar to molding. They have also been produced by the application of successive adhesive coatings of asphalt or similar material, each coating being surfaced with granular surfacing material to increase the thickness and serve to bind and maintain the superimposed asphalt coating in its place and to prevent plastic movement thereof under the action of pressure or heat. It also has been proposed to lay successive layers of a base material, such as roofing felt commonly used in sheet roofing material, upon each other to obtain the increased thickness.

In the present invention, for the purpose of obtaining increased thickness while avoiding a proportionate increase in the weight of the materials used, advantage is taken of the properties of materials which may have portions thereof. especially when in the form of a web of felted bers, expanded in raised prominences or elevations. Such a material is disclosed in United States Letters Patent to William Gerb, No. 2,045,384, issued June 23, 1936. By the process of this patent a sheet of fibrous material, such as a roofing felt, having such an open structure that the fibers contained therein under suitable applications of force may be moved relative to each other, is treated so as to expand said structure into a larger volume. In this way the density of the ordinary felted sheet may be decreased. The specific process disclosed in said Patent No.

urated base sheet of ller materials usually iny 2,045,384 produces a sheet of felted liber having Y portions thereof expanded in this manner upon one face of the sheet with corresponding depressions at the opposite face of the sheet, the general thickness of the sheet being greater than that of the original material of felted fiber, the sheet also having an insulating quality as described in the patent. 'I'he invention, however, may utilize base sheets having portions expanded in other forms and by other processes or may 10 utilize sheetsprovided with raised portions or elevations formed without expansion of the structure of said portions.

- For some purposes in the present invention I may utilize such a sheet having, for example, 15 expanded portions or elevations which may be in the form of knobs which are on one side of the sheet and formed with such height and with such expanded volume that. a coating of waterproof adhesive material, such as asphalt, applied 2o over the general surface of said sheet will cover these expanded portions or knobs and may fill in between these portions and form a continuous surface upon which surfacing material, such as granular slate, may be applied in the usual manner common in roofing practice. Preferably the sheet may be of roofing felt and after treatment for producing the expanded portions may be saturated with a water resisting saturant. In order to secure a fabric which may be saturated 30 with asphalt and thereafter may be coated with a coating of asphalt, and which may be cut into shingles or elements as in ordinary roofing practice, which fabric, in itself, because of the expanded condition thereof will provide a greater thickness than fabric from which it is produced, the portions thereof which are expanded or the knobs may be made close together or contiguous or may be continuous for a considerable distance in a given direction, or may be made to cover a substantial area of the sheet, so as to reduce to 40 the desired degree the amount of area of the original sheet which is left unexpanded or not elevated. The separation or spacing of the knobs, however, may be sufficient to maintain a substantial web of the unexpanded material between 45 the knobs.

lIt is a feature of the invention broadly to prol vide a base suitable for cutting into covering elements, such as roofing sheets or strips or 50 shingles, which sheet will be formed with raised portions or with expanded portions upon the part of said sheet or element which is to be exposed in the roof construction. Such a sheet or element preferably may have the part thereof which 55- is to be overlapped by another sheet or element, or which will be otherwise protected, formed without such' raised or expanded portions or with raised portions of different height on the two parts. The invention includes more specifically the formation of such raised or expanded portions with less height or with less extent upon the part of the sheet or of the element overlapped by another sheet or element than upon the part to be exposed. Moreover, gradual reduction or variation of size of the raised portions is contemplated in some cases to produce elements or shingles of tapering thickness.

While, in the process disclosed in said Patent No. 2,045,384, corresponding depressions are made in the reverse side of the sheet, these depressions are of less extent upon the surface of the sheet than the knobs or expanded portions of the fabric which are raised above the rst mentioned face of the sheet of felt or fabric. Upon this reverse side may be applied a coating of asphalt to cover the relatively large proportion of the area of the surface of the original felt or fabric. By suitably controlling the consistency and viscosity of the asphalt or the adhesive applied to the reverse side of the expanded fabric or felt, the coating maybe caused to fill the depressions in this side or, on the other hand, may be kept upon the surface of this felt or fabric between these depressions leaving them open. Also by suitably controlling the consistency and the capillary quality of this asphalt coating these depressions may be bridged over and covered by the asphalt coating.

Lamination of a plurality of sheets, at least one of which has such raised portions, and the reinforcement of the coatings or of laminations of adhesive between Sheets are contemplated within the invention. Y

The invention will be described in greater detail in connection with the drawings in which- Fig. 1 is a section and Fig. 2 is a face view of a roofing element embodying the invention.

Fig. 3 is a modified form of a portion of the element of Fig. 1.

Fig. 4 is an assembly of elements of the type shown in Fig. 1. i

Fig. 5 is a section of a sheet embodying a modification of the invention.

Fig.`6 illustrates a further modification of the invention.

Figs. 7, 8 and 9 illustrate modifications of the invention by which the tapering section of the covering is secured, Fig. 7 being a section on line 1-1 of Fig. 8.

Figs.' 10 and 11 illustrate av further modified form of the covering having a tapered section, Fig. 11 being a section on line I|-II of Fig. 10.

Fig. l2 shows a laminated form .of the invention.

' Fig. 13 shows a face view of a laminated element embodying the invention and provided with reinforcement between the lamina. y Fig. 14 is a section on line I4-I4 of Fig. 13. Fig. 15 shows another laminated and reinforced form of the invention.

Fig. 16 shows a modification of the invention utilizing a corrugated base sheet with reinforcement.

Fig. 17 is a section of a shingle element embodying the invention and utilizing a modified form of embossing of the base.

Fig. 18 is a face view -of portions of the shingle element of Fig. 17.-.-

Fig. 19 shows a shingle of tapering section embodying the invention and utilizing laminated layers. V

In Fig. 1 the covering material I is shown formed with a base sheet 3 which may be of felt of the type commonly used in the manufacture of roofing. By a process such as is disclosed in said Patent No. 2,045,384, or by other suitable process, portions 5 of the felt before it is saturated with a. bituminous saturant, such as asphalt, are expanded at one side of the felt, corresponding depressions 1 being made in the opposite side of the felt. In the particular ernbodiment illustrated in Figs. 1 and 2 these expanded portions or knobs 5 are formed upon a portion only of the area of the roofing sheet, leaving the portion 9 of the sheet without the expanded portions or knobs 5. As shown in Fig. 2, such a sheet may be cut transversely of its length into shingle elements each having upon the portion thereof to be exposed the raised knobs or expanded portions 5 and upon the area of the shingle to be overlapped by a superimposed course no raised portions, so that the overlapped shingle may bear upon the fiat surface of the sheet beneath.

In producing the roofing sheet or the roofing -elements or`shingles of the invention, the base sheet 3 may be saturated after forming the expanded portions or knobs 5, it being possible by suitable means to traverse the sheet lengthwise through the saturating bath or beneath sprays to cause the fibrous structure of the sheet to absorb the asphalt as in ordinary roofing practice.

By avoiding any substantial pressure upon the raised and expanded portions 5, as the sheet is so delivered and traversed through the bath of saturant, this saturating operation may be carried out without substantially modifying the form of or the expanded condition of the raised and expanded portions 5. To'accomplish this, if necessary, the pull rolls may be designed only to contact portions of the sheet which have no knobs thereon. Moreover, after saturation of the sheet is accomplished, this sheet may be treated in the usual manner in which sheet roofing is prepared, to apply upon the upper face of the saturated base 3 a coating II of waterproof material, such as asphalt. This coating may be applied upon the portion 9 of the saturated base 3 with a thickness substantially the same as is usually applied in the preparation of roong materials. Upon the portion of the sheet or element to be exposed the coating II may be applied, if desired, so as to fill the space between the knobs and produce a fiat surface I2 upon said coatingto which may be bound in the usual manner granular surfacing material I3 such as granular slate. -Upon the portion of the coating II which is to be overlapped by a superimposed element or sheet granular material I5 of smaller grain size or of contrasting character to the granular material I3 may be applied. Y

If desired, by suitable control of the consistency, temperature and amount of the material applied over the knobbed area of the sheet, the coating I I may be caused to cover the surface oi the knobs and to conform to the contour of said knobbed area upon the face of the sheet or element, as shown in Fig. 3. Various degrees of filling the spaces between the knobs may be secured by such control. As in ordinary roofing practice, the under face of the base sheet 3 after saturation thereof may have applied thereto a coating I1 which may be surfaced with a com minuted mica or with other finely divided ma terial. As illustrated in Fig. 1 thisvcoating does not extend deeply into the depressions 'l which are formed in the under face of the sheet in producing the knobs or expanded portions 5. By suitable control of the consistency, temperature and amount of the coating applied to the under face of the sheet, avoidance of filling the depressions l may be obtained. In this way, when the elements are laid on the roof, and particularly when the face of the element having the depressions therein is laid upon the relatively smooth surface of the portion of the element intended to be overlapped by a superimposed element or course, air pockets are formed which may provide an insulating quality in the roof. Fig. 4 shows an assembly of the elements of Fig. l in which this result is obtained. f

Fig. 5 illustrates a modification of the invention in which knobs or expanded portions 5 are formed upon the under face of the sheet. These knobs or expanded portions in this embodiment may be formed over the entire area of the sheet or element instead of only upon the portions thereof to be exposed. .In the covering material illustrated in Fig. 5, upon the upper face of the base sheet 3, preferably after saturation thereoi, may be applied a coating 20 which, in this particular embodiment. fills `the depressions 'l and binds to itself in the usual manner a surfacing I2 of granular material. Upon the under face, and covering the knobs 5, a relatively thin coating I1 is applied following the contour of the surface formed by the knobs 5. When a sheet or element having the form illustrated in' Fig. 5 is applied to the roof, the air spaces between the knobs or expanded portions may act as air pockets producing heat insulation. The upper surface of the covering illustrated in Fig. 5, as will be apparent, is substantially the same as that of ordinary roofing and may be treated in the various ways in which, at present, roofingis treated to provide a finished surface.

Fig. 6 shows a portion of the roofing sheet similar to that of Fig. 5 in which the coating 20 does not iill 'the depressions l but closes these depressions as air pockets which provide a heat insulating property in the covering. Suchva result may be obtained by suitably controlling the consistency, viscosity and amount of the coating so applied to the sheeti"" The underface of the knobs 5 and the face ofthe base sheet 3 may be coated with a coating Il in the same manner as shown in Fig. 5, or, if desired, a complete filling of the spacesbetween the knobs or expanded portions 5 or any degree ofsuch lling may be practiced.

In the manufacture of roofing and of the felt which is used as the base carrying the saturant and the waterproofing or weather resisting material, such as asphalt, attempts heretofore have been made to produce a shingle of tapering thickness by making the felt with varying thickness at diierent portions of the sheet. As such felts are made in a paper making process, by which fibers in suspension in water are laid upon a supporting apron or screen and the water is extracted from the web of fibers, it has been dicult or impossible so to control the delivery of the fibers to different areas of the supporting apron or screen that they will be laid in different determined thicknesses on different parts of said apron or screen. It is particularly diicult or impossible so to control the disposition of the fiber upon the web or screen that a gradual variation in the thickness from one porof the sheet.

tion of the area to another is attained, especially a-predetermined gradation or taper. It, therefore, has been impractical, heretofore, to produce a shingle of such roofing material having tapering thickness by virtue of tapering thickness of the base web of fibers.

It is a feature of the invention, which constitutes an improvement on the invention of said Patent No. 2,045,384, that the expanded portions or knobs 5 may be formed in a roofing felt with varying heights and volumes so that when such an expanded'v felt is treated with saturating and coating materials, as in the ordinary roofing process, a shingle of tapering thickness isI secured, By varying the size of the sockets and of the corresponding pins in the r'olls disclosed in the Patent No. 2,045,384 which are used to produce the expanded portionsor knobs 5, these knobs may be made with diiferent heights and may cover larger and smaller areas and occupy greater' and less volume in the different portions As illustrated in Fig. '7 adjacent an edge 30 of the base sheet 3, knobs 5 may be formed with a large volume and considerable height. The adjacentknobs, proceeding towards the opposite edge 32 of the sheet, may be formed ,with less height and' less volume and successively the other knobs, proceeding in the direction towards said opposite edge 32 of the sheet, may be made with less height and volume. Correspondingly, the depressions 'I made in the underface of the sheet are, successively, of less depth and' less volume in the directionproceeding towards said opposite edge of the sheet.

When such a base felt, illustrated in Fig. 7 without the applied coating and surfacing materials, is 4saturated with asphalt or other saturant, there is secured a base for covering materials or elements having a thickness greater at one portion than at the other' and tapering from one edge thereof toward the other edge. The various ways of applying the coating and surfacing materials, as illustrated in Figs. 1, 2, 3, 5 and 6, may be used in the treatment of the base sheet illustrated in Fig. 7, 'to secure in connection with this embodiment of the invention, the different features and advantages and illustrated in said gues.

As will be seen fom Fig. 8, which is a face View of Fig, 7, the knobs or expanded portions 5 may be arranged in line in the direction proceeding from edge 30 toward the edge 32. As illustrated in Fig. 9, however, the knobs or' expanded portions 5 may be arranged in staggered rows and successively smaller, proceeding in the direction from the edge 30 to the edge 32 and kif desired may be so graded in size that a portion of the sheet may be left without said knobs 5. If desired the larger knobs may be omitted adjacent the edge of the sheet toproduce a step at said edge. Other arrangements of the knobs or expanded portions as to size and as to their relation to each other upon the face of the sheet may be made. For example, as shown in Fig. 9. such knobs may be made of rectangular outline and arranged as diamonds upon the face of the sheet while securing the feature f reduction of the dimensions of the knobs and particularly of the height thereof, in the direction from the edge 3U towards thc edge 32. Such rectangular forms of they knobs are advantageous in securing a sheet with a large portionv thereof expanded,'it being possible to reduce thespaces between the knobs in a rectangular arrangement over that using knobs of circular form.

A further modlcation of the taper form of the shingle illustrated in Figs. 7 and 8 is shown in Fig. l0, Fig. 11 being a section on line il-H of Fig. 10. In this figure a line of knobs, as

5' illustrated in Figs. 7 and 8, may be considered to be developed into a continuous ridge 35, reducing in height from the edge 30 -to the edge 32. Such a ridge will produce a stii sheet from which roofing elements may be cut with the edge l 30 as the edge to be exposed thereof. When the base sheet 3, from which such elements are to be cut, is saturated and coated and surfaced in the manner which has been described above, a stii roong element having a tapering section l and having a thick body is obtained. These features are secured while at the same time securing a relatively light element, because of the expanded or loosened structure of the felt obtained by a process, such as that of the said 30 Patent No. 2,045,384, or by another process, and

one which has the insulating quality provided by the depressions 36 which are produced in the expanding process. It will be understood, however, that the various forms of the invention illustrated in the drawings, including those forms by which tapered shingles are obtained, may be produced with felts of the ordinary type in which raised portions or knobs are formed but are not expanded.` A further modification of the invention is shown in Fig. 12, in which a plurality of sheets of material, such as roong felt having raised portions which, preferably, are expanded in the manner described above, are laminated together. In the particular embodiment shown, the laminations and 4| are provided with the raised expanded portions or knobs 5 having on the opposite face of the sheet corresponding recesses or depressions 1 produced by the process of the 40 Gerb Patent No. 2,045,384, or by any other suitable process. In the particular i embodiment shown, the asphalt lamination 42 binds the base sheets 40 and 4| together and iills the depressions or recesses 1. For the purpose of produc- 45 ing a roofing unit capable of resisting the weather the base sheets 40 and 4| are saturated with a saturant such as asphalt. Such a laminated and impregnated composite base may serve as the base for different treatments by which may be produced diierent types of roofing elements. In the particular embodiment illustrated' in Fig. 12, when the laminations 40 and 4i are properly held together by the asphalt adhesive layer 42, to the composite base thus formed may be applied a coating of weather-resisting and waterproofing material 44, which may cover the knobs 5 and may ll in the spaces therebetween. This application of the coating 44 may beaccomplished by several 50 known methods. For example, the composite base may be dipped in a bath of asphalt at a temperature to give the proper liquid consistency so that the exterior face of the portion of the base on which the Aexpanded knobs are formed 05 will be covered, in the manner illustrated, to provide a protecting layer of asphalt over the tops of the knobs 5 and one which, by filling in the spaces therebetween, will provide an even surface upon the face of the coating thus ap- 70 plied. This coating may also be applied by other methods known in the art, such as the socalled overlay method by which, from a spout or spray, coating is applied to the face of the saturated lamination as it is moved past such a spout or spray.

The coating 44 applied by such methods. of course, may extend over the "end edge of this composite base and may join the asphalt adhesive layer 42, thus providing a seal for the edges of the laminations 40 and 4I and complete enr velopment of the portions of the covering or covering element which is intended to be exposed in the covering construction such as a roof composed of units or elements in overlapping rarrangement. In the particular embodiment shown l0 in Fig. 12 the adhesive coating also is extended upon the part of the composite base which is formed by the portions of the laminations 40 and 4i which are not provided with the expanded knobs 5. The coatings 46 and 41 upon these por- 15 tions may be applied thereto by a dipping or overlay method or by other methods. In some cases it may be necessary after the application of a coating in liquid form and before setting thereof to subject the surface so covered to the 20 action of a doctor blade or similar device to oreate the smooth surface upon the .element which is usually desired for a covering unit such as a rooilng shingle. By the overlay method, with suitable control of its application, the portion of 25 the coating 44 which covers the end of the composite base may be applied to\ said end.

In Fig. 13 is shown the face view of a rooting strip having in the particular embodiment illustrated three tabs separated by the cut-outs. In 2 Fig, 14 is shown a section on line |4-I4 of the shingle tab of Fig. 13. The construction in Figures 13 and 14 is similar to that of Fig. 12 with respect to the lamination of two felts 50 and 5I held together by an adhesive layer of asphalt 52. The laminations 50 and'5l are provided with expanded portions or knobs 5 and with corresponding recesses I on the opposite side of the sheets 5B and 5I. Fig. 13 shows the knobs or expanded portions 5 arranged staggered in rows extending o transversely of the edge to be exposed 54 of the shingle strip, the size of each knob in the row becoming smaller in the direction from said edge 54 of the shingle. The number of said knobs 5 arranged in each of the several rows of knobs illustrated in Fig. 13 may be varied, but in the particular embodiment shown they extend to a point somewhat above the inner end of the cutouts 56 between the tabs of the shingle. If desired, these rows may cover the full extentof 50 the shingle transverse to its edge to be exposed 54 in the manner which has been illustrated in Figures '7 and 8 above described. In this manner a tapering shingle may be produced having a thick butt edge. By the control of the appli- 55Y cation of the enveloping coating 58 the tops of the knobs 5 may be covered and the spaces therebetween may be filled so that a smooth surface is provided upon the face of the'shingle for the application of surfacing material or other treat- 60 i ment suitable for such roofing units, if desired.

In Figures 13 and 14 reference number 50 represents fibers, which may be of various materials, extending in the direction transversely of the edge 54 to be exposed of the shingle. 'I'hese bers S0 o5 are shown in cross section in Fig. 14 in which view, as a particular embodiment of this phase of 1 the invention, said bers 60 are adjacent each lamination 50 and 5i and embedded in the asphalt layer 52 which adhesively joins the base 10 sheets 50 and 5I. Although in Fig. 13 the fibers 60 are shown extending completely across the shingle transversely of the edge 54 thereof, if desired the fibers may extend only part way from the edge 54 toward the rear edge 55 of the shingle. referably, the fibers are placed in such relation to the laminations 50 and 5I of the covering illustrated in Figures 13 and 14 that they will extend for a substantial distance across the tabs or the portions to be exposed of the shingle at least.

If desired, also, as illustrated in Fig. 15, the fibers 60 may be laid between the rows of knobs and parallel to said rows upon the face of the laminations 50 and 5| on which said knobs are formed, so as to occupy a part of the space between the rows of knobs 5.

The fibers 60 described in connection with Figures 13, 14 and 15 may be of grass, jute, hemp or sisal, or of hair or similar long length vegetable or animal 'fiber which, by hand or byany other suitable operation, may be laid ac-ross the face of the shingle prior to the application of the coating 52 or the coating 58 by which said bers are to be joined to the base laminations 50 and 5I. In some cases mineral fibers, such as rock wool or asbestos, though not having the length of some fibrous materials of organic origin, may be suitable for the purpose, By the choice of suitable fibers, particularly those, suc-h as palm leaves or bamboo fiber, which in themselves may have a certain resistance to fiexure transversely of their length, a considerable rigidity may be added to the composite covering material formed in the manner described in connection with Figures 13, 14 and 15. While in the particular embodiment described in connection with Figures 13, 14 and 15 a shingle strip is shown in which, in the preferred manner, the fibers are placed transversely to the edge to be exposed 54 thereof, broadly this phase of the invention contemplates the placing of such fibers across a base sheet in any desired direction or in several directions, said fibers preferably being held in place upon such a base sheet by an adhesive, such as asphalt or other waterproofing and Water-resisting mastic material, so as to cooperate with the knobs, ridges or other raised portions in securing the desired rigidity of the composite sheet. AThe adhesive may for some purposes be of some other type, such as a resin or a drying oil capable of being applied in a plastic or mastic state which will cause the fibers to cooperate with the base sheet to resist exure thereof transversely of the length of the fiber.

I am aware that it has been proposed heretofore to increase the resistance to flexure of roofing elements, such as individual shingles and strip shingles, for the purpose of preventing the blowing up of the exposed end of the element, or the tabs of the strip shingle, by adhesively securing to a flat roofing sheet fibers extending transversely of said exposed end. In the particular embodiment of the invention illustrated in Fig. 13 or in individual shingles, preferably, therefore, the length of the fiber is placed transversely to the lower edge 54. In its function as a tension member or by the inherent stiffness of the fiber itself, resisting exure, or because of both qualities, the fiber acts with the raised portions or knobs to stiffen the sheet. Bending or blowing up of the shingle or of the tab thus substantially may be prevented. When the liber is of such character that it may best ac-t as a tension member rather than because of its stiffness, preferably the arrangement, of the fibers will be that illustrated in Fig. 15 in which they are placed more remotely from the center line between the two laminations 50 and 5I. In some cases, however, the application of the fibers upon those faces of the laminations 50 or 5| which are opposite to those on which the knobs are formed may be more readily accomplished and, by the choice of the fibers, for example by the use of some of the coarse grasses such as pampas, palm leaf, broom corn or similar materials a substantial stifiening of the units transversely of the direction of the fibers incorporated therein may be secured.

It will be noted that in the embodiments of the invention described in connection with Figures 12, 13, 14 and 15, the thick compositely formed covering material is obtained without the duplication of coatings applied to a base such as has ybeen necessary in the practice heretofore. Commonly, heretofore, the base sheet of relatively little thickness in itself has been coated with an adhesive, such as asphalt, to bind thereto a layer of granular material. Thereafter and over the first coating of granular surfacing material there has been applied, by the process of overlaying or by the process of dipping the covering, a second coating of an adhesive such as asphalt serving to bind upon the double coated portions a second layer of granular surfacing material- In the embodimentof the present invention being described in connection with Figures 12, 13, 14 and 15, a single coating of the asphaltvis applied upon the base, although portions of this single coating may have greater thickness than the thickness upon the other portions and may be of greater thickness than that commonly applied in the manufacture of covering materials such as roofing heretofore.

The extra thickness of the covering and of the roofing element, such as shingles and shingle strips which may be made therefrom, is obtained as has been described above by the form of the base, such as the ordinary roofing felt. Especially when such base materials are formed with portions thereof expanded to increase the volume occupied by said portions of the base in the manner described in Patent No. 2,045,384, or in any other suitable manner, the covering or covering elements may be produced with a considerably greater thickness and with a considerable reduction in weight for a given thickness as compared with products as heretofore manufactured. It is desirable to obtain the greater thickness without any substantial increase in the weight of the material which will cover a given area of the roof in order to avoid subjecting the roof structure to an increased load. On the other hand, the weight of the finished material should be sufficient or the combined action of its weight and its stlffening should be such that the material does not readily flex or tear or blowup under the action of wind. The present invention in its various phases provides the solution of these problems. In the embodiment shown in Fig. 1 the additional amount of asphalt carried by the covering between the knob portions serves to increase the stiffness of the covering or elements cut therefrom. Moreover, a base having raised portions itself will be of stiffer form than ordinary flat sheets of roofing felt or similar base material. The cooperation of the knobs or raised portions with the additional asphalt will provide a shingle of considerable thickness and resistance to any mechanical action tending to cause damage to the shingle. Especially where a complete envelopment of the base is provided, as shown in Figures 12 and 13, etc., a markedly improved cooperation of the base sheet and the asphalt materials impregnating and coating the base sheet is secured.

Within the scope of the invention, therefore, is included a covering material having a base sheet, 6 a part of which is embossed to provide raised portions whether or not said raised portions are expanded into a greater volume as suggested in the patent to Gerb No. 2,045,384. By such an embossed sheet is meant a sheet in which de- 10 pressions upon the opposite face of the sheet are formed corresponding with the raised portions on a given face of the sheet, said depressions and raised portions on each face of the sheet preferably being alternately arranged in a plurality of l5 directions so that the mere corrugation of the sheet is avoided. In some cases, however, a corrugated sheet, that is one in which ridges and grooves are formed across the sheet, especially if these ridges are formed with an expanded structure in the manner described in connection with Figures 10 and l1 above, may be so treated as to fill the grooves of one or both sides of the sheet to form an even surface upon either or both sides of the covering, which surface may be treated in diierent ways, such as =the application of granular surfacing material in the manner now practiced in the art. In the use of such base materials in which the structure of the base itself is not expanded to form the raised portions the combination of fibers of considerable length and of the character above in connection with Figures 13, 14 and 15 may be particularly advantageous, such fibers not only adding to the stiffness of the covering or the elements or shingles cut therefrom but serving as reinforcement of the asphalt or other adhesive or coating applied in and filling the grooves. The fibers. therefore. may be laid parallel to the ridges, that is in the grooves, in the manner shown in Fig. 16 in which fibers 60 are laid in the grooves of the corrugated base 62 and are embedded in the coatings 64 and 65 upon this base and lling said grooves to form a covering of uniform thickness. One embodiment of the invention which utilizes f a base having a portion thereof embossed is shown in Fig. 17 in which the base 10 has a portion 1| left without embossing and a portion 12 which is embossed to form elevations 14 of similar form and height at either side of the base 50 10. As will be seen from Fig. 18 the raised portions 14 are interspersed in staggered relation with the depressions 16 therebetween. provided an overall greater vthickness of the portion 12 of the base 10 than that of the portion 55 1 I thereof. Such a base 10, before or after impregnation with a suitable saturant such as asphalt, may be embossed in the manner illustrated to form a covering having a thick portion or to form covering elements having the portion thereof to be exposed of greater thickness than the A portion thereof to be overlapped by other elements. When such a saturated base, itself having an overall greater thickness in the portion thereof to be exposed, is treated to apply thereto by the overlay process or by dipping a coating 19 of asphalt or other mastic or adhesive a covering `or roofing element of substantial thickness may be'secured, to which covering may be applied granular material or other finishing treatment.

70 Such a covering or covering element may have the edge 18 thereof covered by the coating 19 which also may extend upon the under face of the element as illustrated. If desired this coating may also extend upon the portions 1I of the base 10 or this portion 1| may be separately treated for its protection. When a substantial thickness of coating 19 is applied upon the under face of the portion 12 of the base 10 this coating may be caused to adhere to the portion 1| of the base lustrated in Fig. 19 in which the asphalt layer l0 82 which binds together the base laminations 40 and 4| in the manner illustrated in Fig. 12 is formed with a tapering thickness. The thicker portion of the asphalt layer 82 is adjacent the butt end of the unit or element and the thin porl5 tion thereof is adjacent the opposite edge of the element which when laid in a roof construction will be covered by a superimposed element. 'I'his llatter portion of the element in the particular embodiment illustrated in Fig. 19 has applied to each face thereof relatively light coatings 46 and 41 similar to that illustrated in Fig. l2.

In the various embodiments of the present invention which have been described above in which two base sheets or laminations are adhesively bound together, within the scope of the invention for the purpose of securing light weight and producing a covering with greater thickness or both, I may incorporate in this adhesive layer various materials which are inherently of light weigli.

Such materials may be various fibers such as have been described above in connection with Figures 13 and 14 or they may be other materials of animal'. vegetable or mineral origin. Among the materials which may be suitable for the purpose of a light weight filler for this adhesive layer and especially for incorporation in asphalt when used as an adhesive layer between sheets of base material may be suggested cork, vermiculite. diatomaceous earth, or other material having a low specific gravity or a considerable bulk in proportion to its weight when in its granular or comminuted form or, in the case of fibers, when separated to the individual fibers or groups thereof.

The invention constitutes an improvement in the art of producing base materials for covering materials in sheet form and particularly for covering materials and elements used in the roofing art. The invention provides. broadly, a material which makes possible the production of such coverings and elements with a considerably increased thickness. In its application to the art of producing roofing coverings and elements the invention provides a blank of unsaturated roofing felt having a portion thereof of greater thickness than another portion thereof andparticularly a blank having the portion thereof to be exposed in the roof of greater thickness than that part which is to be overlapped by other elements in the roof construction. Such mate- 30 rials and such blanks also may be made of saturated felt and preferably the felt material may have portions thereof on the part which is to be exposed in the roof construction formed with the structure of the felt expanded before satura- 35 tion to provide the increased thickness. Coverings and covering elements formed from these materials according to the invention may include those in which lthe blanks are cut from unsaturated felt and formed with cut-outs, which blanks are then saturated and then coated with asphalt or similar water and weather resisting materials, in order that alllthe edges of the element, or at' least those whichare to be exposed to the weather. may be coated and sealed by the applied coating. In some cases, however, the cut-outs may be made after saturation but before applying the coating.

A particular advantage of the invention secured in several of the embodiments which have been described is that this sealing of all the edges to be exposed and of the face to be exposed is accomplished with a single application -of the asphalt or Weather-resisting coating, thus avoiding duplication or repetition of processes, as is the present practice in the art, and use of heavy granular materials, such as slate, which at present act to bind the overlaid or additional coatings to the covering. Moreover, the advantages of the invention are obtained by the cooperation of materials, that is lthe asphalt or similar saturant andcoating materials and the fillers or fibers which have been referred to, which are of less cost than the base material, such as roofing felt, upon which these Weather-resisting materials and fillers are applied. It is' possible, therefore, to manufacture coverings and covering elements, especially those which may -be adapted to the construction of roofs and similar coverings, with less cost or with not` a greater cost than heretofore, while obtaining the advantages of a mechanically improved covering and one which when formed as roofing elements makes possible a texture and finish in the roof which, at present, may only be obtained at great expense.

Having thus described the invention I now claim:

1. A covering comprising a sheet of felted material having upon a face thereof a plurality of portions of the felted structure raised above said .face of the sheet to form separated projections,

said projections having the felted structure thereof of less density than the material of the felted sheet'which lies- -between said projections, said sheet upon the other face thereof having depressions in said face at places corresponding to said elevations upon the first face, and a coating of mastic material upon said other face, said coating covering said depressions but leaving said depressions unfilled with said mastic material whereby separated air cells are formed within said covering.

2. A covering element comprising a sheet of felted material having upon a face thereof a plurality of spaced elevations formed of the felted material of said sheet, the material of the elevations being of looser structure than the material of the felted sheet which lies between said elevations, said elevations being of different degrees of loosening in two parts of said face of the sheet to produce an element of two different general thicknesses in said parts of the sheet, said elevations being of gradually decreasing size in a given direction to form an element of tapering general thickness, said element being impregnated with a water resisting saturant and coated upon a face thereof with a water resistant coating composition.

3. A covering comprising a plurality of sheets of felted fibrous structure laminatedA together with an adhesive lamination therebetween and with fibrous material embedded in said adhesive, at least one of said sheets having a plurality of portions of said felted structure raised above the face of the sheet to formv a covering of increased thickness,v said covering carrying upon a face thereof a coating of Water resisting mastic material.

4. A covering comprising a plurality of sheets laminated together, at least one of said sheets being formed with a plurality of portions raised above the face of the sheet to increase the thickness thereof, said sheet having upon the face thereof formed with said raised portions a coating of mastic material extending into the spaces between said raised portions, and fibrous material embedded in said coating between said raised portions.

5. A covering comprising a base of felted fibrous structure having upon a face thereof a plurality of portions of said fibrous structure in spaced relation raised above other portions intermediate the raised portions, an adhesive coating upon said face of said base and extending into said spaces, and fibrousI material embedded in the coating in said spaces. 6. A roofing element comprising a base of felted fibrous material having upon a face thereof a plurality of separated elevations formed of the felted material, the material of said elevations being of looser structure than the material of the felted sheet which lies between said elevations, said element being impregnated with an asphalt saturant and coated upon a face thereof with an asphalt coating composition, said coating carrying granular surfacing material partially embedded therein.

7. A roofing element comprising a sheet of felted fibers having upon the part thereof Which is to be exposed in an assembly of elements in. a roof construction a plurality of portions of .the felted structure raised above the face of the sheet to form separated knobs, said knobs being of looser fibrous structure than the material of the felted sheet which extends immediately about said knobs, said sheet being irnpregnated with a water resisting saturant and coated upon said face with a water resisting coating composition, said element having upon the other face thereof a' plurality of depressions corresponding to said knobs.

8. A water resisting covering comprising a sheet of felted fibrous material having a plurality of spaced elevations formed of said fibrous material, said elevations being of looser fibrous structure than the material of the fibrous sheet lying therebetween, said sheet having formed upon the opposite face thereof depressions corresponding to said elevations, said sheet being impregnated with a water resisting saturant, and a coating of water resisting compound upon said oppositev face, said coating compound extending into said depressions of said opposite face.

9. A water resisting covering element having a portion to be exposed in an assemblyof the elements, comprising at least two base sheets of felted fibrous material laminated together, each of said two sheets having a portion of the area of the face formed into a plurality of spaced elevations of looser fibrous structure than the material of the fibrous sheet lying therebetween, another area of the face of each of said sheets being so formed as to provide less elevation than that of the portion ofthe face having said spaced elevations, said sheets having upon the opposite faces thereof depressions corresponding to said looser elevations and being impregnated with a water resisting saturant, said sheets being positioned with said elevations facing outwardly of the laminated covering element with the portions of the one sheet overlying like portions on the other sheet, said sheets being secured together by means of a mastic adhesive layer, and a coating of water resisting mastic material upon the face of said element.

10. A covering comprising a sheet of felted fibrous material having upon a face thereof a plurality of spaced elevations formed of said iibrous material which are of looser fibrous structure than the material of the fibrous sheet lying therebetween, said sheet upon the other 'face thereof having depressions in said face at places registering with the raised portions on said first face to make said raised portions of hollow form, said sheet being impregnated with a water-resisting saturant, said sheet having upon the face thereof upon which said elevations are formed a coating of weather-resisting mastic material.

11. A covering comprising a sheet of felted fibrous material having upon a face thereof a plurality of spaced elevations formed of said brous material which are of looser iibrous structure than the material of the fibrous sheet lying therebetween, said sheet upon the other face `thereof having depressions in said face at places thereof in which said depressions are formed a coating of weather-resisting mastic material.

12. A covering element comprising a base sheet of felted fibrous structure having upon a face thereof a plurality of separated knobs of said felted structure which are of looser felted structure than the material of the fibrous sheet lying therebetween, said element having upon the other face thereof depressions registering with said knobs to provide a hollow form in said knobs, said knobs being of a height above said first face of the element decreasing in the direction from the butt to the rear edge of the element so as to form a tapering shingle element, said element having the base sheet thereof impregnated with a Waterresisting saturant and having upon a face thereof a coating of water-resisting material.

13. A covering comprising a sheet of felted fibrous material having upon a face thereof a plurality of separated elevations formed of the felted material, the material of said elevations being of looser structure than the material of the felted sheet which lies between said elevations, said sheet being impregnated with an asphalt saturant and coated upon a face thereof with an asphalt coating composition.

CHESTER E. RAHR. 

